Centrifuges having upright axes, especially wobble centrifuges are disclosed, for example, in German patent publication (Open Application--Offenlegungsschrift) DE-OS No. 24 59 796 and in other literature to be mentioned below. This publication, in particular, refers to a product accelerator or distributor coupled with the centrifuge drum, aligned with the source of the product to be centrifuged, adapted, because of the arrangement of openings, to uniformly spread the product upon the interior of the centrifuge drum.
This accelerator has the additional purpose of imparting a rotary movement to the product in the direction of drum rotation so as to conform the rotary velocity at least in part to the rotational speed of the drum, the product entering from the axially aligned or coaxial inlet with practically no rotational component.
Reference may also be had to U.S. Pat. No. 4,153,551 issued May 8, 1979 and the publications and references listed therein, to the publications and references listed in the aforementioned German patent document, namely, U.S. Pat. No. 2,676,707, French Pat. No. 1,094,409, German patent document (Open Application--Offenlegungsschrift) DT-OS No. 23 36 922 and German patent document (Printed Application--Auslegeschrift) DT-AS No. 21 26 069.
In the system of German patent document DE-OS No. 24 59 796, the lateral openings in the distributor or product accelerator are generally formed between flanks which are substantially radial.
Experience has shown that while this system is highly effective, nevertheless problems arise when the product is highly abrasive. In such cases the abrasive wear of these surfaces can destroy them, especially when considerable force or torque must be applied to the product, i.e. the product density or viscosity is high.
A particular problem of this kind can be noted when the system of German patent document (Open Application--Offenlegungsschrift) DE-OS 21 27 458 which provides a wobble centrifuge with a distributor associated with the drum in FIG. 3.
In this system especially the high dynamic forces, coupled with the abrasive war of the ribs brings about a significant deterioration of the distributor and/or breakage thereof under certain conditions.
It is self-understood that such breakage must be avoided at all cost since damage to the product accelerator or distributor may endanger the entire unit and certainly renders the unit inoperative.
Consequently, with prior art centrifuges having product accelerators or distributors of the type described, frequent and periodic maintenance is required to monitor wear of the surfaces and the mechanical stability of the accelerator. When such wear is noted, the distributor is removed and replaced, frequently a time-consuming operation.
An alternative approach utilizes preventive maintenance by replacing the distributor after a given number of operating hours, also an expensive and time-consuming proposition.
The problem is complicated by the fact that frequently the distributing or accelerator surfaces of the distributor are not visible from the exterior and hence the machine must be shut down and generally disassembled, at least in part, even for inspection.
Similar problems are encountered with the systems described in German Pat. Nos. 948,409; 970,399 and 1,197,813.